Obesity is a major global health issue with a prevalence of about 15% worldwide, doubled since 1980s (1). The increasing trend in the incidence and prevalence of obesity  is partially attributed to industrialization and changes in lifestyle (2). Fat infiltration and accumulation into different organs, results in organ damage and failure (3). In the liver, it ends in non-alcoholic fatty liver disease (NAFLD) which may progress to inflammation and fibrosis (4). While NAFLD is a known entity, few studies have investigated the fat infiltration in pancreas and its risk factors (5). Accumulation of fat in pancreas was first introduced by Ogilvie in 1933 (6). Van Geenen and colleagues found that fat deposition in pancreas precedes NAFPD and suggested the term non-alcoholic fatty pancreas disease, when associated with obesity (7). Similar to NAFLD, adipose tissue may cause metabolic dysfunction resulting in cytokines that could result in inflammation and fibrosis (5, 8). It has been suggested that NAFPD might be associated with pancreatic cancer (9).

Moreover, it has been suggested that the degree of fat accumulation in pancreas correlates with increasing BMI, insulin resistance, metabolic syndrome (MS), and β–cell dysfunction, which may eventually lead to development of diabetes mellitus (DM) (10-12). Despite all these, NAFPD is not well investigated. Studying the prevalence of this disease shows different rates of NAFPD between 16% (10) to 35% (13), by abdominal ultrasonography. The endoscopic ultrasonography (EUS) has been one of the best methods for evaluation of pancreatic tissue. EUS provides detailed images of the whole pancreas to identify echotexture, space occupying lesions and pancreatic duct abnormalities. In addition, comparison of echogenicity of the pancreas with those of adjacent organs is possible (14). In one study the prevalence of fatty pancreas was reported to be 27.8% among referrals for EUS (14).

In this study, authors aimed to study the prevalence of fatty pancreas and its risk factors by EUS among patients referred to our endosonography unit, a tertiary center in Tehran.